There are three forums reserved for professionals in the food service industry. Non-professionals are certainly welcome to read those threads, but are asked to refrain from commenting in them.
All the other forums are open to both professionals and non-professionals, and, indeed, serve to connect the two.
If by "non-professional stuff" you mean off-topic, that's what the Late Night Cafe forum is all about. That's where we chat about everything under the sun, so long as it doesn't involve food and cooking.
No not really. The pro forums are meant for people who are chefs or cooks. Many people attending culinary school have never worked in a real kitchen yet they are just going to school. The pro forums are really meant for those who get up everyday and go to a restaurant or hotel etc.